CODEWITHSUNDEEP
hibernate
neo
neo

Reputation: 1404

Why "could not extract resultset" error occurs?

I want to get the record from database by id. Below you can see my query: 

public StudentEntity getStudentById(int id) {
    Session session = sessionFactory.openSession();
    Query query = session.createQuery("from StudentEntity where idstudent = :id").setParameter("id", id);

    StudentEntity studentEntity = (StudentEntity) query.uniqueResult();
    session.close();
    return studentEntity;
}

My StudentEntity class you can see here

My stack trace you can see here With other tables I don't get such error. That's why I suppose that the mistake is in StudentEntity class. What can be reason for this error? How can I solve it? Github page of project here

Upvotes: 0

Views: 734

Answers (2)

spencer7593
spencer7593

Reputation: 108370

Q: What can be reason for this error?

A: The stack trace reveals that MySQL is returning error 1064

You have an error in your SQL syntax;
check the manual that corresponds to your MySQL server version
for the right syntax to use near 
'as docExpir4_3_, studentent0_.docIssueOrgnazation as docIssue5_3_, studentent0_.'
at line 1

This means that Hibernate has attempted to prepare or execute a SQL statement that MySQL doesn't understand. There's a syntax error of some kind. We're going to rule out the use of a reserved word as a column name, as Hibernate should be qualifying column references in SELECT statements. And I think we can rule out an invalid column reference, because MySQL would return a different error (1054) for that condition.

Q: How can I solve it?

A: Capture the SQL being executed.

Enable either DEBUG or TRACE for Hibernate, so it logs the SQL statements it is executing... in the log4j configuration, either 

log4j.logger.org.hibernate.SQL=DEBUG
log4j.logger.org.hibernate.type=TRACE

There really is no substitute for learning how to debug programs that you write.

With that said, MySQL column names that include a space need to be properly escaped. For example, if we execute this SQL statement:

SELECT foo.fee fi AS fo FROM fum foo

MySQL server throws a 1064 syntax error "near 'AS fo '"

We don't get that syntax error if we enclose the column name in backtick characters.

SELECT foo.`fee fi` AS fo FROM fum foo
           ^      ^

With Hibernate native API, we can get the column name enclosed in single backticks.

@Column(name = "`fee fi`")

Using JPA, we can enclose in double quotes

@Column(name = "\"fee fi\"")

Upvotes: 2

v.ladynev
v.ladynev

Reputation: 19956

The reason from the stack trace

'as docExpir4_3_, studentent0_.docIssueOrgnazation as docIssue5_3_, studentent0_.'

One of the columns doesn't have a name studentent0_.. Please, check StudentEntity class.

At least this is incorrect

@Column(name = "Payment type", nullable = true, length = 45)
public String getPaymentType() {
    return paymentType;
}

@Column(name = "docExpire time", nullable = true)
public Date getDocExpireTime() {
    return docExpireTime;
}

Upvotes: 1

Related Questions